So says Marc Ambinder (without the question mark), and while I have no reason to doubt him, I have no independent confirmation either. There'll be much more to discuss tomorrow and in the coming days, but for those of you with Friday nights as barren as my own, there's the injection of (hopefully accurate) political epinephrine you've been waiting up for. Now, get some sleep.

Update: CNN and AP concur: Biden's the guy.

--Christopher Orr